Display device and method of manufacturing same

ABSTRACT

A display device comprises a circuit element layer on a substrate and comprising a thin film transistor, a storage capacitor, and a pixel electrode connected thereto, a display layer comprising an emission layer, an opposite electrode on the emission layer, and a functional layer, a thin encapsulation layer on the display layer, the thin encapsulation layer comprising at least one inorganic layer and at least one organic layer, and a through portion passing through the substrate, the circuit element layer, the display layer, and the thin encapsulation layer, wherein a slope angle of a lateral surface of the display layer adjacent to the through portion is different from that of one of a lateral surface of the substrate, a lateral surface of the circuit element layer, and a lateral surface of the thin encapsulation layer that are adjacent to the through portion.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2016-0113260, filed on Sep. 2, 2016, in the KoreanIntellectual Property Office, the disclosure of which is incorporatedherein in its entirety by reference.

BACKGROUND 1. Field

Aspects of one or more embodiments relate to a light-emitting device anda method of controlling the same.

2. Description of the Related Art

Recently, the purposes of display devices have become diversified.Display devices have also become thinner and more lightweight, and thus,their range of usage has gradually widened. In particular, displaydevices have been used recently in various apparatuses such as monitors,mobile phones, and clocks, and thus various methods of designing thedisplay devices have been studied.

SUMMARY

Aspects of one or more embodiments are directed to a display devicehaving a through portion and a method of manufacturing the same. Theabove embodiments are merely provided as an example, and the scope ofthe inventive concept is not limited thereto.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented embodiments.

According to one or more embodiments, there is provided a display devicecomprising: a substrate; a circuit element layer on the substrate andcomprising a thin film transistor, a storage capacitor, and a pixelelectrode electrically connected to the thin film transistor and thestorage capacitor; a display layer on the circuit element layer, thedisplay layer including an emission layer, an opposite electrode on theemission layer, and a functional layer arranged in at least one of aspace between the emission layer and the opposite electrode and a spacebetween the emission layer and the pixel electrode; a thin encapsulationlayer on the display layer, the thin encapsulation layer including atleast one inorganic layer and at least one organic layer; and a throughportion passing through the substrate, the circuit element layer, thedisplay layer, and the thin encapsulation layer, wherein a slope angleof a lateral surface of the display layer adjacent to the throughportion is different from a slope angle of one of a lateral surface ofthe substrate, a lateral surface of the circuit element layer, and alateral surface of the thin encapsulation layer that are adjacent to thethrough portion.

In some embodiments, the functional layer includes at least one of ahole injection layer, a hole transport layer, an electron injectionlayer, and an electron transport layer.

In some embodiments, the display layer includes at least one of acapping layer and an inorganic barrier layer, the capping layer and theinorganic barrier layer being on the opposite electrode.

In some embodiments, the display device further includes: an additionalinorganic layer on the thin encapsulation layer, the additionalinorganic layer covering a lateral surface of the at least one organiclayer that is adjacent to the through portion and the lateral surface ofthe display layer.

In some embodiments, the additional inorganic layer directly contacts aninorganic insulating layer of the circuit element layer.

In some embodiments, the display device further includes: a stepdifference portion adjacent to the through portion and having anundercut shape.

In some embodiments, the step difference portion is between the displaylayer and the substrate.

In some embodiments, the step difference portion includes: a first layerand a second layer including materials different from each other.

In some embodiments, the substrate includes a resin material.

According to some embodiments of the present invention, there isprovided a method of manufacturing a display device, the methodincluding: forming a circuit element layer on a substrate and includinga thin film transistor, a storage capacitor, and a pixel electrodeelectrically connected to the thin film transistor and the storagecapacitor; forming a display layer on the circuit element layer, thedisplay layer including an emission layer, an opposite electrode, and afunctional layer arranged in at least one of a space between theemission layer and the opposite electrode and a space between theemission layer and the pixel electrode; forming a thin encapsulationlayer on the display layer, the thin encapsulation layer including atleast one inorganic layer and at least one organic layer; and forming athrough portion passing through the substrate, the circuit elementlayer, the display layer, and the thin encapsulation layer, wherein theforming of the through portion is performed by using mechanicalpolishing which removes a portion of at least one of the thinencapsulation layer, the display layer, the circuit element layer, andthe substrate.

In some embodiments, a slope angle of a lateral surface of the displaylayer adjacent to the through portion is different from a slope angle ofone of a lateral surface of the substrate adjacent to the throughportion, a lateral surface of the circuit element layer, and a lateralsurface of the thin encapsulation layer.

In some embodiments, in the forming of the display layer, the functionallayer includes at least one of a hole injection layer, a hole transportlayer, an electron injection layer, and an electron transport layer.

In some embodiments, the forming of the display layer includes:

forming at least one of a capping layer and an inorganic barrier layeron the opposite electrode.

In some embodiments, a polishing tape and a tip are used for themechanical polishing.

In some embodiments, the forming of the through portion includes:forming a preliminary through portion by removing a portion of the thinencapsulation layer and a portion of the display layer via themechanical polishing; and irradiating a laser beam to a locationcorresponding to the preliminary through portion.

In some embodiments, the method further includes: forming an additionalinorganic layer on the thin encapsulation layer in which the preliminarythrough portion has been formed.

In some embodiments, the forming of the circuit element layer includes:forming a step difference portion having an undercut shape, the stepdifference portion being adjacent to the through portion.

In some embodiments, the step difference portion includes: a first layerand a second layer including materials different from each other.

In some embodiments, the forming of the through portion includes:forming a preliminary through portion by removing a portion of thedisplay layer via the mechanical polishing; and irradiating a laser beamto a location corresponding to the preliminary through portion.

In some embodiments, the forming of the through portion includes:forming the through portion by removing a portion of the thinencapsulation layer, the display layer, the circuit element layer, andthe substrate via the mechanical polishing.

A display device and a method of manufacturing the same may reduce orminimize the damage or floating of a layer (or layers) in theneighborhood of a through portion. Also, exfoliation of a layer (orlayers) forming a display device may be prevented or substantiallyprevented. The scope of the inventive concept is not limited by thiseffect.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects will become apparent and more readilyappreciated from the following description of the embodiments, taken inconjunction with the accompanying drawings in which:

FIG. 1 is a view of an upper portion of a display device according to anexample embodiment;

FIGS. 2A-2B are views of an upper portion of a display device accordingto another example embodiment;

FIGS. 3A-3B are equivalent circuit diagrams of a pixel according to anexample embodiment;

FIG. 4 is a cross-sectional view of the display device taken along theline IV-IV of FIG. 1;

FIG. 5 is a cross-sectional view of the portion V of the display deviceof FIG. 4;

FIG. 6 is a cross-sectional view of the portion VI of the display deviceof FIG. 4;

FIGS. 7A-7D are cross-sectional views illustrating a method ofmanufacturing a display device according to an example embodiment;

FIG. 8 is a cross-sectional view of a display device according toanother example embodiment;

FIG. 9 is a cross-sectional view of a display device according toanother example embodiment;

FIG. 10 is an enlarged view of the portion X of the display device ofFIG. 9;

FIG. 11 is an enlarged view of the portion XI of the display device ofFIG. 9;

FIGS. 12A-12D are cross-sectional views illustrating a process ofmanufacturing a display device according to an example embodiment;

FIG. 13 is a cross-sectional view of a display device according toanother example embodiment;

FIG. 14 is an enlarged view of the portion XIV of the display device ofFIG. 13; and

FIGS. 15A-15C are cross-sectional views illustrating a method ofmanufacturing a display device according to another example embodiment.

DETAILED DESCRIPTION

As the inventive concept allows for various suitable changes andnumerous embodiments, exemplary embodiments will be illustrated in thedrawings and described in detail in the written description. An effectand a characteristic of the inventive concept, and a method ofaccomplishing these will be apparent when referring to embodimentsdescribed with reference to the drawings. This inventive concept may,however, be embodied in many different forms and should not be construedas limited to the exemplary embodiments set forth herein.

Hereinafter, the inventive concept will be described more fully withreference to the accompanying drawings, in which exemplary embodimentsof the inventive concept are shown. When description is made withreference to the drawings, like reference numerals in the drawingsdenote like or corresponding elements, and repeated description thereofmay not be provided.

Sizes of elements in the drawings may be exaggerated for convenience ofexplanation. In other words, because sizes and thicknesses of componentsin the drawings are arbitrarily illustrated for convenience ofexplanation, the following embodiments are not limited thereto.

When a certain embodiment may be implemented differently, a specificprocess order may be performed differently from the described order. Forexample, two consecutively described processes may be performedsubstantially at the same time or performed in an order opposite to thedescribed order.

FIG. 1 is a view of an upper portion of a display device 100 accordingto an embodiment. FIGS. 2A and 2B are views of an upper portion of thedisplay device 100 according to another embodiment.

Referring to FIG. 1, the display device 100 includes a display area DAand a non-display area NDA. Pixels P including a display element such asan organic light-emitting diode (OLED) are arranged in the display areaDA and provide a predetermined image. The non-display area NDA is anarea which does not provide an image and includes wirings and drivers(e.g. a scan driver and a data driver) transferring an electric signaland power to apply to the pixels P in the display area DA.

A through portion TH is a hole (an opening) passing through the displaydevice 100. The through portion TH may be in the display area DA and maybe surrounded by a plurality of pixels P. A camera, a sensor, a speaker,a microphone, and/or the like may be mounted to the through portion TH.In some examples, the through portion TH may be a space for a separatemember for a function of the display device 100 or for adding a newfunction.

In an embodiment, as illustrated in FIG. 2A, the through portion TH maybe arranged over the display area DA and the non-display area NDA. Aportion of the through portion TH may be partially surrounded by thepixels P in the display area DA. As illustrated in FIGS. 1 and 2A, thethrough portion TH may be arranged inside the display device 100. Inother embodiments, as illustrated in FIG. 2B, the through portion TH mayextend up to the edge of the display device 100.

FIGS. 3A and 3B are equivalent circuit diagrams of a pixel according toan embodiment.

Referring to FIG. 3A, each pixel P includes a pixel circuit PC connectedto a scan line SL and a data line DL, and an OLED connected to the pixelcircuit PC.

The pixel circuit PC includes a driving thin film transistor T1, aswitching thin film transistor T2, and a storage capacitor Cst. Theswitching thin film transistor T2 is connected to a scan line SL and adata line DL and transfers a data signal Dm input via the data line DLto the driving thin film transistor T1 in response to a scan signal Sninput via the scan line SL.

The storage capacitor Cst, connected to the switching thin filmtransistor T2 and a driving voltage line PL, stores a voltagecorresponding to a difference between a voltage transferred from theswitching thin film transistor T2 and a driving voltage ELVDD suppliedto the driving voltage line PL.

The driving thin film transistor T1, connected to the driving voltageline PL and the storage capacitor Cst, may control a driving currentflowing through the OLED from the driving voltage line PL in response tothe voltage stored in the storage capacitor Cst. The OLED may emit lighthaving predetermined brightness by using the driving current.

Though FIG. 3A illustrates an example in which a pixel P include twothin film transistors and one storage capacitor, the embodiment is notlimited thereto.

Referring to FIG. 3B, the pixel circuit PC may include the driving andswitching thin film transistors T1 and T2, a compensation thin filmtransistor T3, a first initialization thin film transistor T4, a firstemission control thin film transistor T5, a second emission control thinfilm transistor T6, and a second initialization thin film transistor T7.

A drain electrode of the driving thin film transistor T1 may beelectrically connected to the OLED via the second emission control thinfilm transistor T6. The driving thin film transistor T1 receives a datasignal Dm and supplies a driving current to the OLED in response to aswitching operation of the switching thin film transistor T2.

A gate electrode of the switching thin film transistor T2 is connectedto a first scan line SLn, and a source electrode of the switching thinfilm transistor T2 is connected to the data line DL. A drain electrodeof the switching thin film transistor T2 may be connected to a sourceelectrode of the driving thin film transistor T1 and also connected tothe driving voltage line PL via the first emission control thin filmtransistor T5.

The switching thin film transistor T2 is turned on in response to afirst scan signal Sn transferred via the first scan line SLn andperforms a switching operation of transferring a data signal Dmtransferred via the data line DL to the source electrode of the drivingthin film transistor T1.

A gate electrode of the compensation thin film transistor T3 may beconnected to the first scan line SLn. A source electrode of thecompensation thin film transistor T3 may be connected to the drainelectrode of the driving thin film transistor T1 and also connected to apixel electrode of the OLED via the second emission control thin filmtransistor T6. A drain electrode of the compensation thin filmtransistor T3 may be also connected to one of electrodes of the storagecapacitor Cst, a source electrode of the first initialization thin filmtransistor T4, and the gate electrode of the driving thin filmtransistor T1. The compensation thin film transistor T3 is turned on inresponse to a first scan signal Sn transferred via the first scan lineSLn and connects the gate electrode of the driving thin film transistorT1 to the drain electrode of the driving thin film transistor T1,thereby diode-connecting the driving thin film transistor T1.

A gate electrode of the first initialization thin film transistor T4 maybe connected to a second scan line SLn−1. A drain electrode of the firstinitialization thin film transistor T4 may be connected to aninitialization voltage line VL. A source electrode of the firstinitialization thin film transistor T4 may be connected to one of theelectrodes of the storage capacitor Cst, the drain electrode of thecompensation thin film transistor T3, and the gate electrode of thedriving thin film transistor T1. The first initialization thin filmtransistor T4 is turned on in response to a second scan signal Sn−1transferred via the second scan line SLn−1, and performs aninitialization operation of initializing the voltage of the gateelectrode of the driving thin film transistor T1 by transferring aninitialization voltage VINT to the gate electrode of the driving thinfilm transistor T1.

A gate electrode of the first emission control thin film transistor T5may be connected to an emission control line EL. A source electrode ofthe first emission control thin film transistor T5 may be connected tothe driving voltage line PL. A drain electrode of the first emissioncontrol thin film transistor T5 is connected to the source electrode ofthe driving thin film transistor T1 and the drain electrode of theswitching thin film transistor T2.

A gate electrode of the second emission control thin film transistor T6may be connected to the emission control line EL. A source electrode ofthe second emission control thin film transistor T6 may be connected tothe drain electrode of the driving thin film transistor T1 and thesource electrode of the compensation thin film transistor T3. A drainelectrode of the second emission control thin film transistor T6 may beelectrically connected to the pixel electrode of the OLED. The firstemission control thin film transistor T5 and the second emission controlthin film transistor T6 are concurrently (e.g., simultaneously) turnedon in response to an emission control signal En transferred via theemission control line EL, a driving voltage ELVDD is transferred to theOLED, and a driving current flows through the OLED.

A gate electrode of the second initialization thin film transistor T7may be connected to a third scan line SLn+1. A source electrode of thesecond initialization thin film transistor T7 may be connected to thepixel electrode of the OLED. A drain electrode of the secondinitialization thin film transistor T7 may be connected to theinitialization voltage line VL. The second initialization thin filmtransistor T7 is turned on in response to a third scan signal Sn+1transferred via the third scan line SLn+1 and may initialize the pixelelectrode of the OLED.

The other electrode of the storage capacitor Cst may be connected to thedriving voltage line PL. One of the electrodes of the storage capacitorCst may be concurrently (e.g., simultaneously) connected to the gateelectrode of the driving thin film transistor T1, the drain electrode ofthe compensation thin film transistor T3, and the source electrode ofthe first initialization thin film transistor T4.

An opposite electrode of the OLED is connected to a common power voltageELVSS. The OLED emits light by receiving a driving current from thedriving thin film transistor T1.

The pixel circuit PC is not limited to a number of thin filmtransistors, a number of storage capacitors, and the circuit designdescribed with reference to FIGS. 3A and 3B, and a number of thin filmtransistors, a number of storage capacitors, and the circuit design maybe variously changed in a suitable manner.

FIG. 4 is a cross-sectional view of the display device 100 taken alongthe line IV-IV of FIG. 1. FIG. 5 is a cross-sectional view of a portionV of the display device 100 of FIG. 4. FIG. 6 is a cross-sectional viewof a portion VI of the display device 100 of FIG. 4.

Referring to FIG. 4, the display device 100 may include a substrate 101,a circuit element layer 110, a display layer 120, a thin encapsulationlayer 130, and an additional inorganic layer 140. A through portion THmay have a depth corresponding to the entire thickness of the displaydevice 100. The through portion TH may pass through all layers rangingfrom the substrate 101 to the additional inorganic layer 140.

The substrate 101 may include various suitable materials including aglass material, metal, or a plastic material such as polyethyleneterephthalate (PET), polyethylene naphthalate (PEN), and polyimide (PI).In the example in which the substrate 101 includes a plastic material,the substrate 101 may have improved flexibility as compared with anexample in which the substrate 101 includes a glass material.

The circuit element layer 110 includes the pixel circuit PC includingthe thin film transistors and the pixel electrode connected to the pixelcircuit PC described with reference to FIGS. 3A to 3B.

The display layer 120 includes an emission layer, an opposite electrode,and a functional layer. When a hole and an electron respectivelyinjected from the pixel electrode of the circuit element layer 110 andthe opposite electrode of the display layer 120 recombine in theemission layer, an exciton is generated. While the exciton falls from anexcited state to a ground state, the exciton emits light.

The circuit element layer 110 and the display layer 120 are describedbelow.

Referring to FIG. 5, the circuit element layer 110 includes a thin filmtransistor (TFT), a storage capacitor Cst, and a pixel electrode 108electrically connected to the TFT and the storage capacitor Cst. Asillustrated in FIG. 5, the TFT includes a semiconductor layer AC, a gateelectrode GE, a source electrode SE, and a drain electrode DE. Thestorage capacitor Cst includes a first electrode CE1 and a secondelectrode CE2 overlapping each other. The first electrode CE1 and thesecond electrode CE2 are respectively arranged in layers in which thegate electrode GE and the source and drain electrodes SE and DE arearranged.

The semiconductor layer AC may include polysilicon or amorphous silicon.In another embodiment, the semiconductor layer AC may include an oxideof at least one of In, Ga, Sn, Zr, V, Hf, Cd, Ge, Cr, Ti, Zn, and/or thelike. For example, the semiconductor layer AC may include an oxidesemiconductor, such as indium gallium zinc oxide (IGZO), zinc tin oxide(ZTO), and zinc indium oxide (ZIO), and/or the like, or an organicsemiconductor.

The gate electrode GE may be a single layer or multiple layers includingAl, Pt, Pd, Ag, Mg, Au, Ni, Nd, Ir, Cr, Li, Ca, Mo, Ti, W, Cu, and/orthe like. The first electrode CE1 is arranged in the same layer as thatof the gate electrode GE and may include the same or substantially thesame material as that of the gate electrode GE.

The source and drain electrodes SE and DE may be a single layer ormultiple layers including a material having excellent conductivity. Forexample, the source and drain electrodes SE and DE may include Al, Pt,Pd, Ag, Mg, Au, Ni, Nd, Ir, Cr, Li, Ca, Mo, Ti, W, Cu, and/or the like.In other embodiments, the source and drain electrodes SE and DE may betriple layers of Ti/Al/Ti. The second electrode CE2 may be arranged inlayers in which the source and drain electrodes SE and DE are arrangedand may include the same or substantially the same material as those ofthe source and drain electrodes SE and DE.

A buffer layer 102 is between the substrate 101 and the semiconductorlayer AC. A gate insulating layer 103 is between the semiconductor layerAC and the gate electrode GE. An interlayer insulating layer 105 isbetween the first and second electrodes CE1 and CE2 and between the gateelectrode GE and the source and drain electrodes SE and DE. Aplanarization insulating layer 107 is below the pixel electrode 108.

The buffer layer 102 and the gate insulating layer 103 may be a singlelayer or multiple layers including an inorganic material such as SiNxand/or SiOx. The interlayer insulating layer 105 may be a single layeror multiple layers including an inorganic material such as SiOx, SiNx,Al₂O₃, and/or the like. The planarization insulating layer 107 mayinclude an organic material including a general-purpose polymer such aspolymethylmethacrylate (PMMA) or polystyrene (PS), polymer derivativeshaving a phenol-based group, an acryl-based polymer, an imide-basedpolymer, an aryl ether-based polymer, an amide-based polymer, afluorine-based polymer, a p-xylene-based polymer, a vinyl alcohol-basedpolymer, a blend thereof, and/or the like. However, the embodiments arenot limited thereto. In another embodiment, the planarization insulatinglayer 107 may have multiple layers including an inorganic material andan organic material.

For convenience of description, according to the present embodiment, atop-gate type TFT is illustrated having the gate electrode GE above thesemiconductor layer AC. However, in another embodiment, the TFT mayinclude a bottom-gate type TFT.

According to the present embodiment, the first electrode CE1 is arrangedin the layer in which the gate electrode GE is arranged and includes thesame or substantially the same material as that of the gate electrodeGE, and the second electrode CE2 is arranged in the layer in which thesource and drain electrodes SE and DE are arranged and includes the sameor substantially the same material as those of the source and drainelectrodes SE and DE. However, this is merely provided as an example. Inanother embodiment, in high resolution, to increase the channel lengthof a TFT, for example, the driving TFT, and to increase the capacitanceof the storage capacitor Cst, the storage capacitor Cst may overlap theTFT above the TFT. For example, the gate electrode GE of the TFT and thefirst electrode CE1 of the storage capacitor Cst may be the sameelectrode. That is, the gate electrode GE of the TFT overlapping thesemiconductor layer AC with the gate insulating layer 103 disposedtherebetween may also perform the function of the first electrode CE1 ofthe storage capacitor Cst.

The pixel electrode 108 includes various suitable conductive materials.The pixel electrode 108 may include a reflective layer including Ag, Mg,Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, a compound thereof, and/or the like. Inother examples, the pixel electrode 108 may include the reflective layerand a transparent conductive oxide (TCO) layer above and/or below thereflective layer. The pixel electrode 108 may correspond to each pixel.

A pixel-defining layer 109 is above the pixel electrode 108, covers theedge of the pixel electrode 108, and exposes the pixel electrode 108.The pixel-defining layer 109 may include an organic insulating layer andan inorganic insulating layer, or include only one of an organicinsulating layer and an inorganic insulating layer.

The display layer 120 is above the circuit element layer 110. Thedisplay layer 120 includes an emission layer 123 and an oppositeelectrode 127 facing the pixel electrode 108 with the emission layer 123disposed therebetween. The display layer 120 includes functional layers121 and 125 arranged in at least one of a space between the pixelelectrode 108 and the emission layer 123 and a space between theemission layer 123 and the opposite electrode 127. The display layer 120may include a capping layer 128 and/or an inorganic barrier layer 129.

The emission layer 123 may emit one of red, green, and blue lightdepending on corresponding pixels. The emission layer 123 may bearranged at each pixel such as a red, a green, and a blue light-emittingpixel. A first function layer 121 and a second function layer 125 arearranged respectively below and above the emission layer 123.

The first functional layer 121 is between the pixel electrode 108 andthe emission layer 123. The first functional layer 121 may include ahole transport layer (HTL) and a hole injection layer (HIL). The secondfunctional layer 125 is between the emission layer 123 and the oppositeelectrode 127. The second functional layer 125 may include an electrontransport layer (ETL) and an electron injection layer (EIL). The firstand second functional layers 121 and 125 are common to pixels. Forexample, each of the first and second functional layers 121 and 125 maybe arranged over the entire surface of the display area DA (e.g., seeFIG. 1).

The emission layer 123 and the first and second functional layers 121and 125 may include a low molecular organic material or a polymermaterial. In the example in which the emission layer 123 and the firstand second functional layers 121 and 125 include a low molecular organicmaterial, they may include various suitable organic materials such ascopper phthalocyanine (CuPc),N,N′-Di(naphthalene-1-yl)-N,N′-diphenyl-benzidine (NPB),tris-8-hydroxyquinoline aluminum (Alq3), and/or the like. In the examplein which the emission layer 123 and the first and second functionallayers 121 and 125 include a polymer material, the first functionallayer 121 may mostly include an HTL. The HTL may include PEDOT, and theemission layer 123 may include a polymer material such as apoly-phenylenevinylene (PPV)-based material and a polyfluorene-basedmaterial, however, this is merely provided as an example, and theembodiment is not limited thereto.

Though FIG. 5 illustrates the example in which the first and secondfunctional layers 121 and 125 are respectively arranged below and abovethe emission layer 123, this is merely provided as an example, and thedisplay layer 120 may include only one of the first and secondfunctional layers 121 and 125.

The opposite electrode 127 may have one unified body and cover thedisplay area DA (e.g., see FIG. 1) of the substrate 101. The oppositeelectrode 127 may be a semi-transmissive thin metal layer including atleast one metal having a small work function, such as Li, Ca, LiF/Ca,LiF/Al, Al, Mg, Ag, an alloy of Ag and Mg, and/or the like. In someexamples, the opposite electrode 127 may include a transparentconductive oxide layer such as ITO, IZO, ZnO, In₂O₃, IGO, AZO, and/orthe like. In other examples, the opposite electrode 127 may havemultiple layers in which the above-mentioned layers are stacked.

The capping layer 128 may protect the layers below the capping layer128. For example, the capping layer 128 may protect the oppositeelectrode 127, the emission layer 123, and the first and secondfunctional layers 121 and 125. The capping layer 128 may be a singlelayer or multiple layers including an organic material and/or aninorganic material.

The inorganic barrier layer 129 may include LiF. The inorganic barrierlayer 129 may prevent or reduce (e.g., minimize) damage to the layersarranged therebelow (e.g. the emission layer) by high energy of oxygenradicals generated during a process of forming the thin encapsulationlayer 130 (which will be described below), for example, a process offorming a first inorganic layer 131, which may be performed via a plasmachemical vapor deposition process.

Referring to FIG. 4 again, the thin encapsulation layer 130 includes atleast one inorganic layer and at least one organic layer. For example,the thin encapsulation layer 130 may include a first inorganic layer 131and a second inorganic layer 135, and an organic layer 133 therebetween.

The first and second inorganic layers 131 and 135 may include AlN,Al₂O₃, TiN, TiO₂, SiON, SiNx, SiOx, and/or the like. The first andsecond inorganic layers 131 and 135 may protect the display layer 120from moisture.

The organic layer 133 may include a polymer-based material such as PMMA,polycarbonate (PC), PS, an acryl-based polymer, an epoxy-based polymer,polyimide, polyethylene (PE), and/or the like. The organic layer 133 maybe thicker than the first and second inorganic layers 131 and 135. Theorganic layer 133 may relieve internal stress of the first and secondinorganic layers 131 and 135, compensate for a defect of the first andsecond inorganic layers 131 and 135, and planarize the first and secondinorganic layers 131 and 135.

The additional inorganic layer 140 is above the thin encapsulation layer130. An end of the additional inorganic layer 140, for example, an endof the additional inorganic layer 140 adjacent to the through portionTH, extends and covers a lateral surface 130 s of the thin encapsulationlayer 130 and a lateral surface 120 s of the display layer 120. Asillustrated in FIG. 6, the additional inorganic layer 140 may contactthe interlayer insulating layer 105 of the circuit element layer 110. Inthe example in which the additional inorganic layer 140 contacts theinterlayer insulating layer 105 including an inorganic material, theadditional inorganic layer 140 may improve an encapsulationcharacteristic by preventing or substantially preventing lateralmoisture transmission of the display device 100.

As illustrated in FIG. 4, the inner lateral surface of the throughportion TH may be determined by the additional inorganic layer 140covering the lateral surfaces 120 s and 130 s of the display layer 120and the thin encapsulation layer 130, a lateral surface 110 s of thecircuit element layer 110, and a lateral surface 101 s of the substrate101. Thus, the through portion TH may be defined by the additionalinorganic layer 140 covering the lateral surfaces 120 s and 130 s of thedisplay layer 120 and the thin encapsulation layer 130, the lateralsurface 110 s of the circuit element layer 110, and the lateral surface101 s of the substrate 101.

In the present specification, “the lateral surface of a layer A” denotesa side connecting the undermost end of the layer A to the uppermost endof the layer A including a single layer or multiple layers, and “theslope angle of the lateral surface of the layer A” denotes the taperedangle of the above-described side. In the example in which the layer Ais a single layer, the lateral surface of the layer A is arranged on thesame plane as the lateral surface of the layer forming the layer A. Inthe example in which the layer A is multiple layers, the lateral surfaceof the layer A may be arranged on the same layer as each of the lateralsurfaces of the plurality of layers forming the layer A, or may bearranged on a different plane. That is, the lateral surface of the layerA and the lateral surface of each of the plurality of layers forming thelayer A should be understood as different concepts.

Therefore, “the lateral surface of the substrate 101 adjacent to thethrough portion TH” denotes the surface 101 s connecting the undermostend of the substrate 101 adjacent to the through portion TH to theuppermost end of the substrate 101. “The slope angle of the lateralsurface 101 s of the substrate 101 adjacent to the through portion TH”denotes a tapered angle θ₀ of the surface 101 s. “The lateral surface ofthe circuit element layer 110 adjacent to the through portion TH”denotes the surface 110 s connecting the undermost end of the circuitelement layer 110 adjacent to the through portion TH to the uppermostend of the circuit element layer 110. “The slope angle of the lateralsurface 110 s of the circuit element layer 110 adjacent to the throughportion TH” denotes a tapered angle θ₁ of the surface 110 s. Likewise,“the lateral surface of the display layer 120 adjacent to the throughportion TH” denotes the surface 120 s connecting the undermost end ofthe display layer 120 adjacent to the through portion TH to theuppermost end of the display layer 120. “The slope angle of the lateralsurface 120 s of the display layer 120 adjacent to the through portionTH” denotes a tapered angle θ₂ of the surface 120 s. Also, “the lateralsurface of the thin encapsulation layer 130 adjacent to the throughportion TH” denotes the surface 130 s connecting the undermost end ofthe thin encapsulation layer 130 adjacent to the through portion TH tothe uppermost end of the thin encapsulation layer 130. “The slope angleof the lateral surface 130 s of the thin encapsulation layer 130adjacent to the through portion TH” denotes a tapered angle θ₃ of thesurface 130 s.

The slope angles θ₀, θ₁, θ₂, and θ₃ of the lateral surfaces of thelayers 101, 110, 120, and 130 of the display device 100 may havedifferent values due to a process of forming the through portion TH. Inthe case of using mechanical polishing which uses a polishing tape and atip as a partial process of forming the through portion TH, the slopeangle of at least one of the layers 101, 110, 120, and 130, for example,the slope angles θ₂ and θ₃ of the display layer 120 and the thinencapsulation layer 130 have values different from the slope angles ofthe lateral surfaces of the other layers, for example, the slope anglesθ₀ and θ₁ of the substrate 101 and the circuit element layer 110.

FIGS. 7A to 7D are cross-sectional views illustrating a method ofmanufacturing a display device according to an embodiment.

Referring to FIG. 7A, the circuit element layer 110, the display layer120, and the thin encapsulation layer 130 are sequentially formed abovethe substrate 101. As described with reference to FIGS. 4 and 5, thecircuit element layer 110 includes the TFT and the storage capacitor,and the pixel electrode connected to the TFT and the storage capacitor.The display layer 120 includes the emission layer 123, the oppositeelectrode 127, and the first and/or second functional layers 121 and125. The display layer 120 may further include the capping layer 128 andthe inorganic barrier layer 129. Because the materials of the substrate101, the circuit element layer 110, the display layer 120, and the thinencapsulation layer 130 are the same or substantially the same as thosedescribed with reference to FIGS. 4 and 5, repeated descriptions thereofmay not be provided. The layers of the display layer 120 may be formedby thermal evaporation. The first and second inorganic layers 131 and135 of the thin encapsulation layer 130 may be formed by chemical vapordeposition (CVD). The organic layer 133 may be formed by forming amonomer and curing the monomer by using heat or light such as anultraviolet ray.

Referring to FIGS. 7A and 7B, a portion of layers including an organicmaterial, a portion of the thin encapsulation layer 130, and a portionof the display layer 120 are removed by mechanical polishing that uses apolishing tape 10 and a tip 20 arranged above the thin encapsulationlayer 130. While a portion of the thin encapsulation layer 130 and aportion of the display layer 120 are removed by mechanical polishing, apreliminary through portion p-TH passing through the thin encapsulationlayer 130 and the display layer 120 is formed. The preliminary throughportion p-PH may have a depth corresponding to the thickness of the thinencapsulation layer 130 and the display layer 120. The circuit elementlayer 110 may be exposed via the preliminary through portion p-TH.

Depending on mechanical polishing that uses the polishing tape 10 andthe tip 20, the slope angle θ₂ of the lateral surface 120 s of thedisplay layer 120 and the slope angle θ₃ of the lateral surface 130 s ofthe thin encapsulation layer 130 that are adjacent to the preliminarythrough portion p-TH may have different values. The slope angles θ₂ andθ₃ may have different values due to factors such as the shape of the tip20, a polishing order, and that the layers of the display layer 120 andthe thin encapsulation layer 130 include different materials such as anorganic material or an inorganic material.

Referring to the enlarged view of FIG. 7B, respective layers forming thedisplay layer 120 include different materials and may each have a slopeangle having different values depending on the shape of the tip 20 and apolishing order. For example, a slope angle α₁ of the lateral surface ofthe first functional layer 121, a slope angle α₂ of the lateral surfaceof the second functional layer 125, a slope angle α₃ of the lateralsurface of the opposite electrode 127, a slope angle α₄ of the lateralsurface of the capping layer 128, and a slope angle α₅ of the lateralsurface of the inorganic barrier layer 129 may have different values.Likewise, a slope angle β₁ of the lateral surface of the first inorganiclayer 131, a slope angle β₂of the lateral surface of the organic layer133, and a slope angle β₃ of the lateral surface of the second inorganiclayer 135 may have different values.

Because the embodiments use a process of using the polishing tape 10 andthe tip 20, when seen from the direction K of the enlarged view of FIG.7B, the lateral surfaces of the organic layer 133 and the firstinorganic layer 131, which are layers below the second inorganic layer135, may be exposed via a region passing through the second inorganiclayer 135. Likewise, when seen from the direction K of the enlarged viewof FIG. 7B, the lateral surface of at least one of layers ranging fromthe capping layer 128 to the first functional layer 121, which arelayers below the inorganic barrier layer 129, may be exposed via aregion passing through the inorganic barrier layer 129. Likewise, atleast one of layers below the capping layer 128, the opposite electrode127, and the second functional layer 125 may be exposed via regionsrespectively passing through the capping layer 128, the oppositeelectrode 127, and the second functional layer 125.

The polishing tape 10 may be supplied from a polishing tape supplier tothe thin encapsulation layer 130 along a direction “A” and, afterforming the preliminary through portion p-TH, may move toward apolishing tape collector along a direction “B”. As a comparative exampleof the embodiment, in the case of using a polisher rotating in place,replacement of the polisher is required depending on abrasion of thepolisher during mass production, and productivity reduces as time takenfor the replacement increases. However, in the case of using thepolishing tape supplied in one direction according to the embodiment,because a process of replacing the polisher separately is omitted,manufacturing efficiency may improve.

Referring to FIG. 7C, after forming the preliminary through portionp-TH, the additional inorganic layer 140 is formed. The additionalinorganic layer 140 is formed above the entire surface of the substrate101. For example, the additional inorganic layer 140 covers the uppersurface of the thin encapsulation layer 130, the lateral surface 130 sof the thin encapsulation layer 130, the lateral surface 120 s of thedisplay layer 120, and the upper surface of the circuit element layer110 exposed via the preliminary through portion p-TH.

Referring to FIG. 7D, the through portion TH is formed by forming theadditional inorganic layer 140, irradiating a laser beam to a locationcorresponding to the preliminary through portion p-PH, and removing aportion of the circuit element layer 110 and a portion of the substrate101 that correspond to the preliminary through portion p-TH. The throughportion TH may have a depth corresponding to the entire thickness of thedisplay device 100.

The slope angles θ₁ and θ₀ respectively of the lateral surface 110 s ofthe circuit element layer 110 and the lateral surface 101 s of thesubstrate 101, which are formed by a laser process, are different fromthe slope angle θ₂ of the lateral surface 120 s of the display layer 120and the slope angle θ₃ of the lateral surface 130 s of the thinencapsulation layer 130, which are formed by the above-describedpolishing process. The slopes angles θ₀ and θ₁ formed by the laserprocess may have values of about 90° or close to about 90° according tothe depth of field (DOF) of the laser beam.

The through portion TH of the display device 100 described withreference to FIGS. 4 and 7A to 7D may be differentiated from the throughportion formed by only the laser beam. In the case of forming a throughportion by irradiating the laser beam right after forming the displaydevice 100, the slope angles θ₂ and θ₃ may have substantially the samevalues due to the DOF of the laser beam. Also, in the area surroundingthe through portion formed by the laser beam, denaturalization of theorganic material may occur by heat generated while the laser isirradiated, a layer of the organic material may swell up, or the organicmaterial may float, and moisture transmission in the lateral direction(e.g., an interface direction between a layer and a layer) may occur.

However, according to the manufacturing method described with referenceto FIGS. 7A to 7D, because layers including the organic material, forexample, the thin encapsulation layer 130 and the display layer 120 areremoved by the mechanical polishing process and not by the laserprocess, denaturalization of the organic material by heat generatedwhile the laser beam is irradiated, swelling of the layer of the organicmaterial, or floating of the organic material may be prevented orsubstantially prevented.

The through portion TH of the display device 100 described withreference to FIGS. 4 and 7A to 7D may be discriminated from a throughportion formed by a polisher rotating in place. As a comparative exampleof the embodiment, in the case of using a polisher rotating in place,polishing a plurality of layers is not easy, and even if the pluralityof layers are polished, the lateral surfaces of the respective layersmay not have slope angles of different values as in the presentembodiment. Also, because it may not be easy to prevent the dischargeburrs generated while the layers are polished on layers in thesurrounding area of the through portion formed by the polisher rotatingin place, the burrs may adhere to the inner diameter of the throughportion due to frictional heat during the polishing.

FIG. 8 is a cross-sectional view of a display device 200 according toanother embodiment.

Referring to FIG. 8, the display device 200 includes a substrate 201, acircuit element layer 210, a display layer 220, a thin encapsulationlayer 230, and an additional inorganic layer 240. Because the substrate201, the circuit element layer 210, the display layer 220, and theadditional inorganic layer 240 are respectively the same as thesubstrate 101, the circuit element layer 110, the display layer 120, andthe additional inorganic layer 140 described with reference to FIGS. 4and 5, descriptions thereof may not be repeated.

In an embodiment, though the uppermost surface of the thin encapsulationlayer 130 of the display device 100 may be the inorganic layer (e.g.,the second inorganic layer) as described with reference to FIG. 4, theembodiment is not limited thereto. In another embodiment, the uppermostsurface of the thin encapsulation layer 230 illustrated in FIG. 8 may bean organic layer 233. Though the uppermost surface of the thinencapsulation layer 230 is the organic layer 233, because the additionalinorganic layer 240 is arranged above the thin encapsulation layer 230,the display layer 220 may be protected from moisture, and/or the like

The thin encapsulation layer 230 may include an inorganic layer 231 andthe organic layer 233. The inorganic layer 231 and the organic layer 233respectively include the same or substantially the same materials asthose of the first inorganic layer 131 and the organic layer 133described above with reference to FIG. 4.

The slope angles θ₀, θ₁, θ₂, and θ₃ of the lateral surfaces of layers201, 210, 220, and 230 of the display device 200 according to thepresent embodiment may have different values as a result of a process offorming the through portion TH. In the case of using mechanicalpolishing that uses a polishing tape and a tip as a process of formingthe through portion TH, the slope angles θ₀, θ₁, θ₂, and θ₃ of thelateral surfaces of layers 201, 210, 220, and 230 have different values.

Because the display device 200 illustrated in FIG. 8 is manufactured bysubstantially the same process as the process described with referenceto FIGS. 7A and 7B, repeated descriptions thereof may not be provided.

FIG. 9 is a cross-sectional view of a display device 300 according toanother embodiment, FIG. 10 is an enlarged view of a portion X of thedisplay device 300 of FIG. 9, and FIG. 11 is an enlarged view of aportion XI of the display device 300 of FIG. 9.

Referring to FIG. 9, the display device 300 includes a substrate 301, acircuit element layer 310, a display layer 320, a thin encapsulationlayer 330, and a step difference portion 350.

Because the substrate 301, the circuit element layer 310, and thedisplay layer 320 are respectively the same as the substrate 101, thecircuit element layer 110, and the display layer 120 described abovewith reference to FIGS. 4 and 5, descriptions thereof may not berepeated.

The thin encapsulation layer 330 may include an organic layer 333between first and second inorganic layers 331 and 335. The organiclayers 133 and 233 of the thin encapsulation layers 130 and 230 of thedisplay devices 100 and 200 are not directly exposed toward the throughportion TH, however, the lateral surface of the organic layer 333 of thethin encapsulation layer 330 according to the present embodiment may bedirectly exposed toward the through portion TH.

Referring to FIG. 10, the first inorganic layer 331 may not directlycontact an interlayer insulating layer 305 in the surrounding area ofthe through portion TH. In some examples, even when the first inorganiclayer 331 directly contacts the interlayer insulating layer 305 in thesurrounding area of the through portion TH, the first inorganic layer331 may contact a very small area of the interlayer insulating layer305. A buffer layer 302, a gate insulating layer 303, and the interlayerinsulating layer 305 are inorganic layers and it is difficult formoisture to penetrate into an interface between these inorganic layers,however, because the first inorganic layer 331 covering the displaylayer 320 in the surrounding area of the through portion TH directlycontacts the interlayer insulating layer 305 and does not seal a lateralsurface 320 s of the display layer 320, moisture, and/or the like maypenetrate into the display layer 320. However, according to someembodiments, a step difference portion 350 is arranged adjacent to thethrough portion TH and may block a penetration path of moisture, and/orthe like.

Referring to FIG. 11, the step difference portion 350 has an undercutshape. The step difference portion 350 includes a first layer 351 and asecond layer 353 above the first layer 351, in which the first andsecond layers 351 and 353 have different widths. For example, the firstlayer 351 has a width w0 less than a width w1 of the second layer 353.The step difference portion 350 may be arranged below the display layer320.

The first and second layers 351 and 353 include different materials. Forexample, the first layer 351 may include a metallic material and thesecond layer 353 may include an insulating material. The first layer 351may include the same or substantially the same material as that of oneof an electrode of the TFT and an electrode of the storage capacitor Cstdescribed with reference to FIG. 5. In an embodiment, the first layer351 may be arranged above the buffer layer 302 and the gate insulatinglayer 303 and may include the same or substantially the same material asthat of the gate electrode described with reference to FIG. 5. Also, thesecond layer 353 may include the same or substantially the same materialas that of the interlayer insulating layer 305.

Layers above the step difference portion 350, for example, the displaylayers 320 including a first functional layer 321, a second functionallayer 325, and an opposite electrode 327 may be disconnected from eachother by the undercut-shaped step difference portion 350. Even whenmoisture penetrates in the lateral direction of the display layer 320,for example, when moisture penetrates via an interface between the firstfunctional layer 321, the second functional layer 325, and the oppositeelectrode 327, because a penetration path is blocked by the stepdifference portion 350, penetration of the moisture to a pixel may beprevented or substantially prevented.

Referring to FIG. 9 again, the slope angles θ₀, θ₁, θ₂, and θ₃ oflateral surfaces 301 s, 310 s, 320 s, and 330 s of the layers 301, 310,320, and 330 of the display device 300 may have different values due toa process of forming the through portion TH. For example, in the case ofusing mechanical polishing that uses a polishing tape and a tip as apartial process of forming the through portion TH, the slope angle (e.g.the slope angle θ₂ of the lateral surface 320 s of the display layer320) of one of the layers 301, 310, 320, and 330 may have a valuedifferent from the slope angles of the lateral surfaces of the otherlayers, for example, the slope angles θ₀, θ₁, and θ₃ of the lateralsurfaces 301 s, 310 s, and 330 s of the substrate 301, the circuitelement layer 310, and the thin encapsulation layer 330.

FIGS. 12A to 12D are cross-sectional views illustrating a process ofmanufacturing a display device according to an embodiment.

Referring to FIG. 12A, the circuit element layer 310 and the displaylayer 320 are sequentially formed above the substrate 301. The circuitelement layer 310 includes a TFT, a storage capacitor, and a pixelelectrode connected to the TFT and the storage capacitor. The displaylayer 320 includes an emission layer, an opposite electrode, a firstfunctional layer and/or a second functional layer. The display layer 320may further include a capping layer and/or an inorganic barrier layer.The materials of the substrate 301, the circuit element layer 310, andthe display layer 320 are the same or substantially the same as thosedescribed with reference to FIGS. 4 and 5, and a manufacturing methodthereof is the same or substantially the same as that described withreference to FIG. 7A.

A process of forming the circuit element layer 310 may include a processof forming a step difference portion 350. As described with reference toFIG. 11, the step difference portion 350 may include the first layer 351and the second layer 353. The first layer 351 and the second layer 353include the materials described above. In an embodiment, the undercutshape of the step difference portion 350 may be formed during an etchingprocess of a pixel electrode. For example, while a metallic materialforming the first layer 351 is etched by an etchant used for the etchingprocess of the pixel electrode, the first layer 351 may have the widthw0 less than the width w1 of the second layer 353.

Referring to FIGS. 12A and 12B, a layer including an organic material,for example, a portion of the display layer 320, is removed bymechanical polishing that uses the polishing tape 10 and the tip 20arranged above the display layer 320. The polishing tape 10 may besupplied from a polishing tape supplier to the display layer 320 along adirection “A” and, after forming the preliminary through portion p-TH,may move toward a polishing tape collector along a direction “B”.

While a portion of the display layer 320 is removed by mechanicalpolishing, the preliminary through portion p-TH passing through thedisplay layer 120 is formed. The preliminary through portion p-TH mayhave a depth corresponding to the thickness of the display layer 120.The circuit element layer 310 may be exposed via the preliminary throughportion p-TH.

The lateral surface 320 s of the display layer 320 may have a slopeangle θ₂ as a result of mechanical polishing that uses the polishingtape 10 and the tip 20. Though FIG. 12B illustrates only the slope angleθ₂ of the lateral surface 320 s of the display layer 320, as describedwith reference to FIG. 7B, respective layers forming the display layer320 include different materials and have slopes (slope angles) ofdifferent values depending on the shape of the tip 20 and a polishingorder, and layers therebelow may be exposed via a through region of oneof the layers.

Referring to FIG. 12C, after forming the preliminary through portionp-TH, the thin encapsulation layer 330 is formed. The thin encapsulationlayer 330 includes the first and second inorganic layers 331 and 335 andthe organic layer 333 therebetween. The materials and the manufacturingprocess of the first and second inorganic layers 331 and 335 and theorganic layer 333 are the same or substantially the same as thosedescribed above.

Referring to FIGS. 12C and 12D, the through portion TH is formed byirradiating a laser beam to a location corresponding to the preliminarythrough portion p-TH and removing a portion of the thin encapsulationlayer 330, a portion of the circuit element layer 310, and a portion ofthe substrate 301 corresponding to the preliminary through portion p-TH.The through portion TH may have a depth corresponding to the entirethickness of the display device 300.

The slope angles θ₃, θ₁, and θ₀ of the lateral surface 330 s ofrespectively the thin encapsulation layer 330, the lateral surface 310 sof the circuit element layer 310, and the lateral surface 301 s of thesubstrate 301 formed by the laser process are different from the slopeangle θ₂ of the lateral surface 320 s of the display layer 320 formed bythe above polishing process. The slope angles θ₃, θ₁ and, θ₀ formed bythe laser process may have values of about 90° or close to about 90°according to the depth of field (DOF) of the laser beam.

FIG. 13 is a cross-sectional view of a display device 400 according toanother embodiment and FIG. 14 is an enlarged view of a portion XIV ofthe display device 400 of FIG. 13.

Referring to FIG. 13, the display device 400 includes a substrate 401, acircuit element layer 410, a display layer 420, a thin encapsulationlayer 430, and a step difference portion 450.

Because the substrate 401, the circuit element layer 410, and thedisplay layer 420 are respectively the same as the substrate 101, thecircuit element layer 110, and the display layer 120 described withreference to FIGS. 4 and 5, descriptions thereof may not be repeated.

The thin encapsulation layer 430 may include first and second inorganiclayers 431 and 435, and an organic layer 433 therebetween. Like the thinencapsulation layer 330 described above, the organic layer 433 of thethin encapsulation layer 430 may be directly exposed toward the lateralsurface of the through portion TH.

In an embodiment, as illustrated in FIG. 14, the thin encapsulationlayer 430 of the display device 400 does not directly contact aninterlayer insulating layer 405 in the surrounding area of the throughportion TH. That is, a first functional layer 421, a second functionallayer 425, an opposite electrode 427, and/or the like of the displaylayer 420 may be directly exposed to the through portion TH. A bufferlayer 402, a gate insulating layer 403, and an interlayer insulatinglayer 405 are inorganic layers and it is difficult for moisture topenetrate via an interface therebetween, however, because the displaylayer 420 is exposed, moisture, and/or the like may penetrate via aninterface between layers forming the display layer 420. However,according to some embodiments, an undercut-shaped step differenceportion 450 is arranged adjacent to the through portion TH and may blocka penetration path of moisture, and/or the like. Because the stepdifference portion 450 has the same structure described above withreference to FIG. 10, a description thereof may not be repeated.

The slope angles θ₀, θ₁, θ₂, and θ₃ of the lateral surfaces of thelayers 401, 410, 420, and 430 of the display device 400 may havedifferent values due to a process of forming the through portion TH. Forexample, in the case of using mechanical polishing that uses a polishingtape and a tip for a process of forming the through portion TH, theslope angles θ₀, θ₁, θ₂, and θ₃ of the layers 401, 410, 420, and 430 mayhave different values.

FIGS. 15A to 15C are cross-sectional views illustrating a method ofmanufacturing a display device according to another embodiment.

Referring to FIG. 15A, the circuit element layer 410, the display layer420, and the thin encapsulation layer 430 are sequentially formed overthe substrate 401. Also, a protective film layer 460 is formed on thethin encapsulation layer 430.

The circuit element layer 410 includes a TFT, a storage capacitor, and apixel electrode connected to the TFT and the storage capacitor. Thedisplay layer 420 includes an emission layer, an opposite electrode, andfirst and/or second functional layers. The display layer 420 may furtherinclude a capping layer and/or an inorganic barrier layer. The thinencapsulation layer 430 includes the first and second inorganic layers431 and 435, and the organic layer 433 therebetween. The materials ofthe substrate 401, the circuit element layer 410, the display layer 420,and the thin encapsulation layer 430 are the same or substantially thesame as those described with reference to FIGS. 4 and 5, and themanufacturing method thereof is the same or substantially the same asthat described with reference to FIG. 7A. As described with reference toFIG. 12A, a process of forming the circuit element layer 410 may furtherinclude a process of forming the step difference portion 450. The stepdifference portion 450 is the same or substantially the same as the stepdifference portion 350 described with reference to FIG. 11.

The protective film layer 460 protects the display device from foreignsubstances, and/or the like during the process. For example, theprotective film layer 460 may include various suitable materials such asPET, PEN, PI, and/or the like.

Referring to FIGS. 15A and 15B, the through portion TH is formed byremoving portions of the protective film layer 460, the thinencapsulation layer 430, the display layer 420, the circuit elementlayer 410, and the substrate 401 by mechanical polishing that uses thepolishing tape 10 and the tip 20 arranged above the protective filmlayer 460. The polishing tape 10 may be supplied from a polishing tapesupplier to the thin encapsulation layer 430 along a direction “A” and,after forming the through portion p-TH, may move toward a polishing tapecollector along a direction “B”.

The through portion TH formed by mechanical polishing has a depthcorresponding to the entire thickness of the display device 400.

Depending on mechanical polishing that uses the polishing tape 10 andthe tip 20, the slope angles of respective layers of the display device400, for example, a slope angle θ₄ of a lateral surface 460 s of theprotective film layer 460, a slope angle θ₃ of a lateral surface 430 sof the thin encapsulation layer 430, a slope angle θ₂ of a lateralsurface 420 s of the display layer 420, a slope angle θ₁ of a lateralsurface 410 s of the circuit element layer 410, and a slope angle θ₀ ofa lateral surface 401 s of the substrate 401 may respectively havedifferent values.

After that, as illustrated in FIG. 15C, the protective film layer 460 isremoved.

Because the embodiments use a process of using the polishing tape 10 andthe tip 20, when seen from a direction K of the enlarged view of FIG.15C, the lateral surfaces of the display layer 420, the circuit elementlayer 410, and the substrate 401, which are layers below the thinencapsulation layer 430, may be exposed via a region passing through thethin encapsulation layer 430. The lateral surfaces of the circuitelement layer 410 and the substrate 401 may be exposed via a regionpassing through the display layer 420. The lateral surface of thesubstrate 401 may be exposed via a region passing through the circuitelement layer 410.

Also, like the description made with reference to the enlarged view ofFIG. 7B, the slope angles of the respective layers (e.g. an inorganicbarrier layer, a capping layer, an opposite electrode, a secondfunctional layer, and a first functional layer) locally forming thedisplay layer 420 may have different values and a layer (or layers)therebelow may be exposed via a through region of the respective layers.Similarly, the slope angles of respective layers forming the thinencapsulation layer 430, the circuit element layer 410, and thesubstrate 401 may have different values, and a layer (or layers)therebelow may be exposed via a through region of the respective layers.

Though the embodiments described with reference to FIGS. 14 and 15A to15C have described the example in which a mechanical polishing processusing the polishing tape 10 and the tip 20 is performed in a directionfrom the protective film layer 460 to the substrate 401, according toanother embodiment, the mechanical polishing process may be performed ina direction from the substrate 401 to the protective film layer 460.Even in this case, similarly with the above embodiment, the slope anglesof respective layers may have different values.

It will be understood that, although the terms “first”, “second”,“third”, etc., may be used herein to describe various elements,components, regions, layers and/or sections, these elements, components,regions, layers and/or sections should not be limited by these terms.These terms are used to distinguish one element, component, region,layer or section from another element, component, region, layer orsection. Thus, a first element, component, region, layer or sectiondiscussed below could be termed a second element, component, region,layer or section, without departing from the spirit and scope of theinventive concept.

Spatially relative terms, such as “beneath”, “below”, “lower”, “under”,“above”, “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. It will beunderstood that the spatially relative terms are intended to encompassdifferent orientations of the device in use or in operation, in additionto the orientation depicted in the figures. For example, if the devicein the figures is turned over, elements described as “below” or“beneath” or “under” other elements or features would then be oriented“above” the other elements or features. Thus, the example terms “below”and “under” can encompass both an orientation of above and below. Thedevice may be otherwise oriented (e.g., rotated 90 degrees or at otherorientations) and the spatially relative descriptors used herein shouldbe interpreted accordingly. In addition, it will also be understood thatwhen a layer is referred to as being “between” two layers, it can be theonly layer between the two layers, or one or more intervening layers mayalso be present.

The terminology used herein is for the purpose of describing particularembodiments and is not intended to be limiting of the inventive concept.As used herein, the singular forms “a” and “an” are intended to includethe plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “include,”“including,” “comprises,” and/or “comprising,” when used in thisspecification, specify the presence of stated features, integers, steps,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof. As used herein,the term “and/or” includes any and all combinations of one or more ofthe associated listed items. Expressions such as “at least one of,” whenpreceding a list of elements, modify the entire list of elements and donot modify the individual elements of the list. Further, the use of“may” when describing embodiments of the inventive concept refers to“one or more embodiments of the inventive concept.” Also, the term“exemplary” is intended to refer to an example or illustration.

It will be understood that when an element or layer is referred to asbeing “on”, “connected to”, “coupled to”, or “adjacent” another elementor layer, it can be directly on, connected to, coupled to, or adjacentthe other element or layer, or one or more intervening elements orlayers may be present. When an element or layer is referred to as being“directly on,” “directly connected to”, “directly coupled to”, or“immediately adjacent” another element or layer, there are nointervening elements or layers present.

As used herein, the term “substantially,” “about,” and similar terms areused as terms of approximation and not as terms of degree, and areintended to account for the inherent variations in measured orcalculated values that would be recognized by those of ordinary skill inthe art.

As used herein, the terms “use,” “using,” and “used” may be consideredsynonymous with the terms “utilize,” “utilizing,” and “utilized,”respectively.

Though the inventive concept has been described with reference to theembodiments illustrated in the drawings, this is merely exemplary and itwill be understood by those of ordinary skill in the art that varioussuitable changes in form and details and equivalents thereof may be madetherein without departing from the spirit and scope of the inventiveconcept as defined by the following claims and equivalents thereof.

What is claimed is:
 1. A display device comprising: a substrate; acircuit element layer on the substrate, the circuit element layercomprising a thin film transistor, a storage capacitor, and a pixelelectrode electrically connected to the thin film transistor and thestorage capacitor; a display layer on the circuit element layer, thedisplay layer comprising an emission layer, an opposite electrode on theemission layer, and a functional layer arranged in at least one of aspace between the emission layer and the opposite electrode and a spacebetween the emission layer and the pixel electrode; a thin encapsulationlayer on the display layer, the thin encapsulation layer comprising atleast one inorganic layer and at least one organic layer; and a throughportion passing through the substrate, the circuit element layer, thedisplay layer, and the thin encapsulation layer, wherein a slope angleof a lateral surface of the display layer adjacent to the throughportion is different from a slope angle of one of a lateral surface ofthe substrate, a lateral surface of the circuit element layer, and alateral surface of the thin encapsulation layer that are adjacent to thethrough portion.
 2. The display device of claim 1, wherein thefunctional layer comprises at least one of a hole injection layer, ahole transport layer, an electron injection layer, and an electrontransport layer.
 3. The display device of claim 1, wherein the displaylayer comprises at least one of a capping layer and an inorganic barrierlayer, the capping layer and the inorganic barrier layer being on theopposite electrode.
 4. The display device of claim 1, furthercomprising: an additional inorganic layer on the thin encapsulationlayer, the additional inorganic layer covering a lateral surface of theat least one organic layer that is adjacent to the through portion andthe lateral surface of the display layer.
 5. The display device of claim4, wherein the additional inorganic layer directly contacts an inorganicinsulating layer of the circuit element layer.
 6. The display device ofclaim 1, further comprising: a step difference portion adjacent to thethrough portion and having an undercut shape.
 7. The display device ofclaim 6, wherein the step difference portion is between the displaylayer and the substrate.
 8. The display device of claim 6, wherein thestep difference portion comprises: a first layer and a second layercomprising materials different from each other.
 9. The display device ofclaim 1, wherein the substrate comprises a resin material.
 10. A methodof manufacturing a display device, the method comprising: forming acircuit element layer on a substrate and comprising a thin filmtransistor, a storage capacitor, and a pixel electrode electricallyconnected to the thin film transistor and the storage capacitor; forminga display layer on the circuit element layer, the display layercomprising an emission layer, an opposite electrode, and a functionallayer arranged in at least one of a space between the emission layer andthe opposite electrode and a space between the emission layer and thepixel electrode; forming a thin encapsulation layer on the displaylayer, the thin encapsulation layer comprising at least one inorganiclayer and at least one organic layer; and forming a through portionpassing through the substrate, the circuit element layer, the displaylayer, and the thin encapsulation layer, wherein the forming of thethrough portion is performed by using mechanical polishing which removesa portion of at least one of the thin encapsulation layer, the displaylayer, the circuit element layer, and the substrate.
 11. The method ofclaim 10, wherein a slope angle of a lateral surface of the displaylayer adjacent to the through portion is different from a slope angle ofone of a lateral surface of the substrate adjacent to the throughportion, a lateral surface of the circuit element layer, and a lateralsurface of the thin encapsulation layer.
 12. The method of claim 10,wherein in the forming of the display layer, the functional layercomprises at least one of a hole injection layer, a hole transportlayer, an electron injection layer, and an electron transport layer. 13.The method of claim 10, wherein the forming of the display layercomprises: forming one of a capping layer and an inorganic barrier layeron the opposite electrode.
 14. The method of claim 10, wherein apolishing tape and a tip are used for the mechanical polishing.
 15. Themethod of claim 10, wherein the forming of the through portioncomprises: forming a preliminary through portion by removing a portionof the thin encapsulation layer and a portion of the display layer viathe mechanical polishing; and irradiating a laser beam to a locationcorresponding to the preliminary through portion.
 16. The method ofclaim 15, further comprising: forming an additional inorganic layer onthe thin encapsulation layer in which the preliminary through portionhas been formed.
 17. The method of claim 10, wherein the forming of thecircuit element layer comprises: forming a step difference portionhaving an undercut shape, the step difference portion being adjacent tothe through portion.
 18. The method of claim 17, wherein the stepdifference portion comprises: a first layer and a second layercomprising materials different from each other.
 19. The method of claim17, wherein the forming of the through portion comprises: forming apreliminary through portion by removing a portion of the display layervia the mechanical polishing; and irradiating a laser beam to a locationcorresponding to the preliminary through portion.
 20. The method ofclaim 17, wherein the forming of the through portion comprises: formingthe through portion by removing a portion of the thin encapsulationlayer, the display layer, the circuit element layer, and the substratevia the mechanical polishing.